An important electronic component of a radio frequency (RF) transceiver is a field-effect transistor (FET) that makes up stacked FET-type RF switches. An RF switch that is FET based typically needs linearity compensation to prevent generation of harmonic distortion when transmit signals are applied to the RF switch while the RF switch is in an off-state. The RF switch is effectively open while in the off-state, and the transmit signals are prevented from passing through the RF switch. However, while the RF switch is open, undesirable harmonics are generated from the transmit signals in part due to non-linear capacitance inherent to the RF switch. The undesirable harmonics pass from the RF switch and interfere with the RF transceiver's receiver circuitry.
A traditional off-state linearization network is placed in parallel with the RF switch to reduce the undesirable harmonics. While the traditional off-state linearization network does reduce the harmonic distortion when transmit signals are applied to the RF switch in the off-state, the traditional off-state linearization network takes up valuable circuit real estate because it requires external bias circuitry. Moreover, there is a growing need for RF switches to perform under hot switching conditions in which transmit-level RF signals are present at terminals of the RF switch as the RF switch transitions from the off-state to the on-state and vice versa. What is needed is an RF switch that is structured to regain valuable real estate by way of off-state linearization networks that do not require external bias circuitry and that switches reliably under hot switching conditions.